From: Sage Weil <sage@redhat.com>
Date: Sat, 10 Dec 2016 23:00:46 +0000 (-0600)
Subject: osd: remove 'rlat' read latency metrics
X-Git-Tag: v12.0.0~334^2~10
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=e94521638b13eccb7ad94c89d36b66b52fe7002a;p=ceph.git

osd: remove 'rlat' read latency metrics

These are measuring how long of a delay we see before ops are readable.
They are calculated in the on_applied path, which we'd like to remove,
and weren't reliably calculated anyway.

Signed-off-by: Sage Weil <sage@redhat.com>
---

diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index 9c795aff7a4a..4f430384c5dc 100644
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -2521,8 +2521,6 @@ void OSD::create_logger()
       "Client write operations");        // client writes
   osd_plb.add_u64_counter(l_osd_op_w_inb,  "op_w_in_bytes",
       "Client data written");    // client write in bytes
-  osd_plb.add_time_avg(l_osd_op_w_rlat, "op_w_rlat",
-      "Client write operation readable/applied latency");   // client write readable/applied latency
   osd_plb.add_time_avg(l_osd_op_w_lat,  "op_w_latency",
       "Latency of write operation (including queue time)");    // client write latency
   osd_plb.add_time_avg(l_osd_op_w_process_lat, "op_w_process_latency",
@@ -2535,8 +2533,6 @@ void OSD::create_logger()
       "Client read-modify-write operations write in");   // client rmw in bytes
   osd_plb.add_u64_counter(l_osd_op_rw_outb,"op_rw_out_bytes",
       "Client read-modify-write operations read out ");  // client rmw out bytes
-  osd_plb.add_time_avg(l_osd_op_rw_rlat,"op_rw_rlat",
-      "Client read-modify-write operation readable/applied latency");  // client rmw readable/applied latency
   osd_plb.add_time_avg(l_osd_op_rw_lat, "op_rw_latency",
       "Latency of read-modify-write operation (including queue time)");   // client rmw latency
   osd_plb.add_time_avg(l_osd_op_rw_process_lat, "op_rw_process_latency",
diff --git a/src/osd/OSD.h b/src/osd/OSD.h
index 7e089c9868be..28ecab2a5d6a 100644
--- a/src/osd/OSD.h
+++ b/src/osd/OSD.h
@@ -73,14 +73,12 @@ enum {
   l_osd_op_r_prepare_lat,
   l_osd_op_w,
   l_osd_op_w_inb,
-  l_osd_op_w_rlat,
   l_osd_op_w_lat,
   l_osd_op_w_process_lat,
   l_osd_op_w_prepare_lat,
   l_osd_op_rw,
   l_osd_op_rw_inb,
   l_osd_op_rw_outb,
-  l_osd_op_rw_rlat,
   l_osd_op_rw_lat,
   l_osd_op_rw_process_lat,
   l_osd_op_rw_prepare_lat,
diff --git a/src/osd/PrimaryLogPG.cc b/src/osd/PrimaryLogPG.cc
index c218f8cd1500..b89c30146806 100644
--- a/src/osd/PrimaryLogPG.cc
+++ b/src/osd/PrimaryLogPG.cc
@@ -3279,13 +3279,6 @@ void PrimaryLogPG::execute_ctx(OpContext *ctx)
 	osd->send_message_osd_client(reply, m->get_connection());
 	ctx->sent_ack = true;
       }
-
-      // note the write is now readable (for rlatency calc).  note
-      // that this will only be defined if the write is readable
-      // _prior_ to being committed; it will not get set with
-      // writeahead journaling, for instance.
-      if (ctx->readable_stamp == utime_t())
-	ctx->readable_stamp = ceph_clock_now();
     });
   ctx->register_on_commit(
     [m, ctx, this](){
@@ -3357,12 +3350,6 @@ void PrimaryLogPG::log_op_stats(OpContext *ctx)
   utime_t process_latency = now;
   process_latency -= ctx->op->get_dequeued_time();
 
-  utime_t rlatency;
-  if (ctx->readable_stamp != utime_t()) {
-    rlatency = ctx->readable_stamp;
-    rlatency -= ctx->op->get_req()->get_recv_stamp();
-  }
-
   uint64_t inb = ctx->bytes_written;
   uint64_t outb = ctx->bytes_read;
 
@@ -3379,8 +3366,6 @@ void PrimaryLogPG::log_op_stats(OpContext *ctx)
     osd->logger->inc(l_osd_op_rw_outb, outb);
     osd->logger->tinc(l_osd_op_rw_lat, latency);
     osd->logger->tinc(l_osd_op_rw_process_lat, process_latency);
-    if (rlatency != utime_t())
-      osd->logger->tinc(l_osd_op_rw_rlat, rlatency);
   } else if (op->may_read()) {
     osd->logger->inc(l_osd_op_r);
     osd->logger->inc(l_osd_op_r_outb, outb);
@@ -3391,15 +3376,12 @@ void PrimaryLogPG::log_op_stats(OpContext *ctx)
     osd->logger->inc(l_osd_op_w_inb, inb);
     osd->logger->tinc(l_osd_op_w_lat, latency);
     osd->logger->tinc(l_osd_op_w_process_lat, process_latency);
-    if (rlatency != utime_t())
-      osd->logger->tinc(l_osd_op_w_rlat, rlatency);
   } else
     ceph_abort();
 
   dout(15) << "log_op_stats " << *m
 	   << " inb " << inb
 	   << " outb " << outb
-	   << " rlat " << rlatency
 	   << " lat " << latency << dendl;
 }
 
diff --git a/src/osd/PrimaryLogPG.h b/src/osd/PrimaryLogPG.h
index dee65e3024cd..943045667245 100644
--- a/src/osd/PrimaryLogPG.h
+++ b/src/osd/PrimaryLogPG.h
@@ -512,7 +512,6 @@ public:
 
     MOSDOpReply *reply;
 
-    utime_t readable_stamp;  // when applied on all replicas
     PrimaryLogPG *pg;
 
     int num_read;    ///< count read ops